NUTRITION, the other side of the energy equationby Patti and Warren Finke, Team Oregon
Tom Nash, Tempe Arizona writes: "Dear Team Oregon Tips ... I am a 5000/10000 Meter runner with a high metabolism and a low body fat... During serious training I am faced with the dilemma of consuming enough calories without eating a lot of meat and fattening foods... How is the energy scheme affected by diet and what realistic options do I have to maximize my racing performance?"
Optimum utilization of the energy systems for training assumes that you ( the runner) are getting an adequate fuel supply. Getting that adequate nutrition during hard training can be a real challenge for athletes. Many runners have a tendency to underfuel themselves especially those worrying about weight control. Underfueling can lead to sluggishness, fatigue, poor performance, injury and even permanent alteration (lowering) of basal metabolism. While we are not dieticians, we are educated in sports nutrition and can give you some basic guidance. We suggest that if you are having problems getting adequate nutrition, it may be helpful to visit a sports dietician or nutritionist to get a dietary plan that works for you.
HOW MUCH TO EATYou can estimate your daily caloric requirements by knowing your BMR ( basal metabolic rate or the calories needed by your body for basic existence) plus the calories burned by your training and other activities during the day. You can estimate your BMR calories by multiplying your body weight by 10. For example a 150 lb person would have an estimated BMR of 1500 calories. Typical daily activity adds somewhere between 300 and 1000 calories per day. If you have a desk job and are fairly sedentary, add 300 calories; add up to 1,000 calories if your job demands physical labor and you're on your feet all day. Each mile of running consumes about 100 calories. Caloric needs per mile are determined by your body weight rather than by how fast you run. The 150 lb athlete with a desk job who averages 10 miles of running per day burns approximately 3000 calories. The food that the athlete eats provides that energy and replaces the calories burned.
WHAT TO EATThe runner, just like every one else, should be eating a healthy well balanced diet with 60 - 70% of the calories being derived from carbohydrates(CHO). About 12 - 15% of your diet should be protein; leaving about 15 - 20% to come from fats (a far cry from the average American diet which averages about 40% fat). You have to have a well balanced diet as well as adequate calories to have adequate nutrition. You need to include foods from the five major food categories as listed in the Food Guide Pyramid from the USDA.
Milk, Yogurt and Cheese GroupYou should have 2 or more servings per day of milk, cheese, yogurt cottage cheese or ice cream to provide calcium, riboflavin, protein and fat. To reduce the fat consumption, pick the low and non fat choices for all these dairy products. If you are not consuming any of these, make certain that you are getting some source of calcium in your diet. Calcium is essential in muscle contraction and endurance runners need about 1200 mg per day.
Meat Group.You should have 2 or more servings per day of meat, fish, poultry, eggs, dry beans, legumes or nuts to provide protein, fat, niacin, iron and thiamine. There are lower fat choices in this group as well. Although many runners avoid red meat, it may be the best source of these nutrients making the once a week meal of super lean hamburger a good choice. Recently, some studies have suggested that the protein needs of long distance runners may be higher than those of weight lifters.
Fruit and Vegetable GroupsYou need 8 or more servings per day from these two groups to provide you with a good source of carbohydrates and vitamins particularly vitamins A & C. At least 2 servings should be fruits.
Grains GroupBreads, cereals, rice and pasta are the major sources of carbohydrates in this group; they also provide other nutrients such as thiamine, niacin and iron. You should be eating more than 8 servings from this group daily.
The Junk Food Group (Fats, Oils and Sweets)Cakes, cookies, pies, candy, soft drinks and alcoholic beverages consist mainly of simple carbohydrates and fat with minimal vitamin, mineral and other nutritional content. These foods should be eaten sparingly to supplement your caloric requirements after you have eaten the recommended serving from the other food groups.
WaterDon't forget that proper hydration is critical for performance. Significant decreases in performance occur after less than 45 minutes of exercise without water replacement. The average adult requires about 4 1/2 pints of water per day for normal metabolism. An additional pint per half hour may be lost during exercise. When exercising heavily in warm weather, you should be consuming fluids on a regular basis throughout your workout. Monitor your weight before and after the exercise and replace the fluid weight loss as soon after exercise as possible by consuming a about a pint per pound.
SupplementsThere is a huge vitamin, mineral, protein powder and other food supplement market. In general, if you eat a well balanced diet with adequate servings from all of the food groups listed above, supplements will only guarantee that you have expensive urine. There are of course, exceptions; for example, if you are lactose intolerant you need to take supplements to get adequate calcium.
WHEN TO EATAn important aspect of training is post exercise glycogen (your carbohydrate energy source) replacement. Without muscle and liver glycogen resynthesis, the body will be chronically depleted and effective training becomes impossible.
The dietary factors that dictate the rate of muscle glycogen resynthesis are : the rate of carbohydrate ingestion, the timing of the carbohydrate ingestion after exercise and the carbohydrate type.
Glycogen resynthesis is at its highest in the first two hours after exercise with a rate as high as 9% if 28 grams of carbohydrate is ingested every 15 minutes. It is important to start and optimize replacement in these first two hours.
After the first two hours, the maximum resynthesis rate is about 5%. This means that even with optimal replacement it will take about 1 day to replenish stores. To keep synthesis at maximum rates, carbohydrate ingestion needs to be at least 50 grams of carbohydrate every 2 hours. Eating much more than 50 grams will not increase the resynthesis rate.
Carbohydrates can be characterized by their ability to convert to blood glucose to be transported by the bloodstream into the muscles and liver. This ability is called glycemic index with classification of high, moderate or low with high being the fastest. The index is regulated by a number of factors and not by whether the CHO is simple or complex. High glycemic food such as glucose, sucrose (table sugar), maltodextrin, syrup, breads, raisins, and potatoes and moderate glycemic index foods such as rice, oatmeal, spaghetti, grapes, oranges and yams are equal at promoting resynthesis at optimal rates. It does not appear to matter if they are in liquid or solid form. Muscle glycogen resynthesis is about 3% per hour with low glycemic index foods such as most fruits, fructose(fruit sugar), most legumes (beans, etc) and dairy products. Low glycemic index foods are important before long workouts to provide slow release energy.
A SUGGESTED STRATEGYHere is a suggested strategy to help you make certain that you are adequately fueled for your training.
First, determine your average daily calorie requirements by analyzing your BMR, activity level and training as discussed above.
Maintain a balanced training diet with 2 servings each from the milk and meat groups and at least 8 serving from each of the fruits and vegetables groups and the grains group. This should provide a minimum of 2500 calories per day. To assure quick recovery from training, eat or drink the high glycemic carbohydrates in your diet immediately after workouts ( up to 100 grams of carbohydrates in the first hour) and 50 g every 2 hours thereafter.
If your caloric requirements are higher than the 2500 calories per day provided by the basic training diet, supplement with calories from high glycemic carbohydrate foods (ie bread) or drinks (ie Gatorade) making certain to get 50 grams (200 calories) every two hours after your workout. Note that some sports drinks are fructose based and are therefore not high glycemic.
Suppose your average workout day consists of a five mile run and your estimated calories consumption is 2500 calories. Your basic training diet would support this caloric requirement. In the first hour after your workout, you consume a large bagel (2 bread servings, 200 calories, high glycemic CHO) and a large glass of orange juice (2 fruit servings, 200 calories, moderate glycemic CHO). Every two hours for the next four hours, try to take in 2 servings of high to moderate glycemic carbohydrate foods, such as breads, potatoes and sports drinks along with plenty of water. This post exercise eating would account for half of your daily bread and fruit servings. The remainder of your nutritional needs should be consumed in your regular meals.
Suppose on a hard workout day you ran 10 miles. This would require about 500 more calories than your normal training diet. You could supplement that diet above by adding and additional 50 grams of high or moderate glycemic carbohydrate every 2 hours for the first four hours after your workout. This could be in the form of a quart of Gatorade or another bagel or better tasting 3-4 chocolate chip cookies.( animal crackers, graham crackers and fruit newtons have less fat, but might not be your choice.
There are any number of books on sports nutrition available at the library or bookstore. For further information on glycemic index and post exercise replacement , read Liz Applegate's column in Runner's World November 1992 or The Physician and Sports Medicine February 1993.
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